1. Field of the Invention
The present invention relates to an inkjet recording apparatus that includes a recording head which has a cap for capping a discharge port of the recording head.
2. Description of the Related Art
Inkjet recording apparatuses record an image by ejecting ink droplets from a fine discharge port formed on a discharge port face, which is disposed on the recording head, and causing those ink droplets to impact on a recording medium.
A problem with inkjet recording apparatuses is that viscosity increases due to evaporating of moisture in the ink from the discharge port and vicinity thereof, which is the portion where the ink contacts the air. Due to this thickened ink, discharge failure such as clogging occurs, and ink discharge becomes unstable.
A known method to counteract this problem is a recovery method in which the ink is replaced by suction and discharge of the thickened ink in the discharge port and vicinity thereof at the start of recording and at fixed time intervals. Another known method is preliminary discharge, in which the ink is discharged to a portion out of a recording area.
On the other hand, it is also known to provide a cap for capping the discharge port face of the recording head during a non-recording operation in which ink is not discharged. By providing a cap, the moisture in the ink can be prevented from evaporating from the discharge port. Further, another known method is to recover from nozzle clogging by discharging ink onto an absorber provided in the cap to keep the interior moist, and leaving the discharge port face in a moist state (e.g., Japanese Patent Application Laid-Open No. 2005-313114).
By using this method, compared with performing suction recovery, an amount of discarded ink can be substantially reduced.
In the method of recovering from clogging by discharging ink into the cap to maintain a moist state, it is necessary to keep the moist state for a long duration until the nozzle recovers from clogging.
In the method discussed in Japanese Patent Application Laid-Open No. 2005-313114, a user selects whether to perform a lengthy moistening recovery or to immediately perform suction recovery. However, when moistening recovery is selected, this document does not discuss performing a recording operation during the lengthy period that the recording head is capped.